Brands, Medical Use, Clinical Data
Brands / Synonyms
Ig gamma-2A chain C region, membrane-bound form; radiolabeled murine anti-CD20; Zevalin (IDEC Pharmaceuticals)
Indium conjugated murine IgG1 kappa monoclonal antibody directed against the CD20 antigen, which is found on the surface of normal and malignant B lymphocytes. Ibritumomab is produced in Chinese hamster ovary cells and is composed of two murine gamma 1 heavy chains of 445 amino acids each and two kappa light chains of 213 amino acids each.
For treatment of non-Hodgkin's lymphoma
Zevalin binds to the CD20 antigen, which is predominantly expressed on mature B cells and on >90% of B-cell non-Hodgkin's lympohomas. The antibody leads to selective killing of B-cells.
Mechanism of Action
Binds to the CD20 antigen which is found on mature B lymphocytes. The Fc domain recruits immune effector functions to mediate B-cell lysis. The antibody appears to induce apoptosis, antibody mediated cytotoxicity and complement-dependent cytotoxicity. The chelate tiuxetan, which tightly binds radioactive In-111 or Y-90, is covalently linked to the amino groups of exposed lysines and arginines contained within the antibody. The beta emission from Y-90 induces cellular damage by the formation of free radicals in the target and neighboring cells.
Biotrnasformation / Drug Metabolism
Most likely removed by opsonization via the reticuloendothelial system when bound to B cells, or by human antimurine antibody production